Drying apparatus



Patented June 16, 1925.

. I-IENRY'BAETZ, OF ST. LOUIS, MISSOURI.

DRYI'NG APPARATUS.

Application led September 25, 1922. SerialNo. 590,477.l

T0 all 'whom t may concern.' w

Be it known that I, HENRY BAE'rz, a citizen of the United States, residing at St. Louis, State of Missouri, have invented certain new and useful Improvements in Drying Apparatus,vof which the following is a specification.

My invention yhas relation to improvements in drying apparatus and consists in the novel features of construction morefully set `forth in the specification and pointed p out in the claims.

It is generally understoodthat, in various drying appara-tus wherein the material to be `dried is fed through a chamber equipped with heating coils or supplied with ablast of heated air, the moisture given off by the material must pass through the casing and necessarily retards the drying operation. Then too, as far as I am aware, there is no provision made for controlling the moisture content of the drying air or the temperature of the casing s0 as to obtain the most suitable drying conditions for different materials. ,l

It is the object of the present invention to provide a drying apparatus wherein both the moisture-content of the drying air and the temperature within the chamber may be controlled throughout the entire extent of said chamber. It is a further object of this invention to `provide a drying apparatus wherein different drying conditions can be effected in different parts of the drying chamber. For instance, if in drying acertain material the best results are obtained by subjecting the material first to a comparatively moist circulation of air and then gradually increasing' the temperature and decreasing the humidity thereof, these conditions can be effected in the drying chamber and varied at Will. This is best accomplished by providing a drying chamber through which the material is fed, said chamber being composed of sections each of which has an independently controlled heater and air circulation, the material bcng fed progressively from section to section until the drying operation is completed. The moisture laden air may be continuously expelled from 'each section without having to pass Athrough any other section, which greatly increases the drying efficiency of the apparatus; A further object is to provide a drying apparatus in which the air circulation is transverse tothe direction of travel longitudinal section through the drier, the 1 middle part of the same being broken away; Fig. 2v is a top` plan of the drier; Fig. 3 is a horizontal section through the drier taken on the line 3 3 of Fig. 1; Fig. 4 is an enlarged vertical cross-section through the, driertaken on the Zig-zag linea-*4 of Fig. 2; Flg. 5 is an enlarged side elevation of a section of the drier with part of the flue broken away'; and Fig. 6 is an enlarged sectional detail 'taken on the line 6.-6 of Fig. 5; and Fig. 7 is an enlarged detail View of part of one of the fresh air dampers showing the quadrant and bolt for holding the dampers in place in front elevation.

Referring to the drawings, H represents a suitable casing which houses the drying chamber C, said chamber being divided into sections S, S', S,\S, etc., each of which comprises a heating compartment 1, and an air circulation compartment 2, said compartments being formed by a horizontal partition member 3 extending longitudinally ,throughout thecasing, and disposed about one-fourth the height of the casing from the top, and by vertical partition walls 4 extending from side to side of the casing and from the ltop wall to the partition member 3. Thus the compartments 1 are completely separated from each other, while the compartments 2 are separatecompartments only in the sense that each has its own air circulation (about to appear) said compartments 2 being in free communication with each other throughout the length of the drying chamber C to permit the continuous'travel of trucks T therethrough, on rails R, said trucks being loaded with the material m to be dried. In each compartment `1 to one side of the middle is a' bank of `steam coils 5, said coils completely filling about one-fourth of the compartment, and two fau casings 6,

vair intake openings 9, 9 and the peripheral wall ofk each casing is provided with an airV outletopening 10.. it being understood that the partition?) is cutout opposite each opening 10 to permit the air from the fan to pass into the compartment 2. 'lhe partition wall 3 is also provided with openings 1l between compartments 1 and 2,`.said openings being on the side of tht` sections S. S', C", etc. opposite to the fan 7. It will be observed that the fans 7 are disposed on opposite sides of adjacent sections S, S', consequently 'there is a shaft. 8 extending throughout the length of the chamber on each side thereof.l The. sections S, S are reversed in other particulars also, the openings 11 heingin staggered relation throughout the chamber 'as wellA as the heating elements 5. The yobject of thus reversing the adjacent sections of the chamber is to cause the air circulated through the drying compartments 2, 2, to travel in op-4 posite dlrections, so that all parts of-the stock or material m will be exposed to the drying air a maximum period of time. It is readily apparent that it the fan in sec?, tion S (Fig. 4) is revolved in the direction of the arrow it will cause a circulation of air downward into compartment 2, where the air will encounter a seriesof deiiectors 12, 12, 12and be directed across the compartment in substantially horizontal paths (see arrows) to the opposite side thereof. when it will be drawn up through opening 11 under influence of the fan intake and through compartment 1 past the heating coils 5 and into the fan, when it is again directed into compartment 2. Thus a continuous circulation of air is created in a closed circuit through compartments 1 and 2. Now'the fans in the next adjacent section S will be revolved in an opposite direction to that in the section just referred to, so that they will create an air circulation opposite to that in section S. The material m will thus be subjected to the drying,r eifect .of the heated air on one side in section S, and as the material is fed on into section S it Will encounter an air circulation directed against it from the opposite side, and so on' throughout the drying chamber.

It is obvious that after the air has circulated in this short circuit through compartments 1 and 2, it will become moisture laden from taking up the moisture in the stock,

` and some meansA must be provided for exdampers 19 will be in front of openings 15 to close these openings. AThus the air 1ntake openings 15, 15 are controlled simultaneously with the air discharge through the flue, the one being opened or closed in proportion as the other is closed or opened. One of the bearings 17 has a quadrant 20 formed with it, said quadrant being provided with a plurality vof openings 21, and

a bolt 22 is mounted on the adjacent damper 19, said bolt being ladapted to enter any one of the openings 21 according to the amount it is desired to open the dampers. Since the dampers 18 and 19 ofeach section S, S, etc. are controlled independent of any other section, it is possible to obtain varying conditions of humidity in the respective sections by varying the positions of these dampers so as to admit variable quantities of fresh air to compartment 1 of each section. Obviously, the more fresh air. that is admitted to any given section the more spent, moisture laden air will be expelled. Some materials require rather exacting drying conditions, and in order to exercise perfect control over the drying conditions I may place a hygrometer 25 in each flue 13 above the dalnper 18, and by noting from time to time the moisture content of the air being expelled through the tiue the operator will know whether to increase or decrease the amount of fresh air admitted to the compartment 1. l

In order that the hygrometer 25 may be read from the outside of the flue, the latter may be provided with Window 26 on its outside Wall.

The shafts 8, 8 each carry a pulley 2 7 on one end, the pulleys 27 being connected by a crossed belt 28, and one of the shafts 8 carries a driving pulley 29 on its other end, so that the shafts 8 (and, of course, the fans 7 mounted on the shafts) will be simultaneously driven in opposite directions. Obviously other .driving means for the 'shafts may be resorted to if desired.

The casing C is provided with doors D, I), at each end through which the material is fed to the casing and discharged therefrom. v

The supply of steam to each heating coil 5 is controlled by a valve o, and a main valve V controls the supply of steam to the entire battery of coils.

Having described my invention, I claim:

1. A drier comprising a suitable' casing gitudinally into a series of juxtaposed sections, each of said sections being divided .into

a fan compartment and a drying compartment in superposed relation, a fanv in each fan compartment operating to circulate air through the drying compartment of the section, and means for causing the air to circulate through the drying compa'tment in substantially'horizontal paths.

2. A drier comprising a suitable casing or chamber,` a succession of air moving Jand 'air heating devices disposed in the upper part of said chamber and operatingto circulate heated air across the chamber laterally in opposite directions 3. A drier comprising a suitable casing or chamber, said chamber lbeing divided longitudinally into a series of juxtaposed sections, each of said Sections being divided into a heating compartment and a drying compartment, an air moving and an air heat. ing device -in each 'heating compartment operating to ccirculate heated air through the drying compartment of the section, and means for. causing the air to circulate through the drying compartment in sub- 1 stantiallyv horizontal paths.

4. A drier comprising a suitable casin or chamber,s'aid chamber being divided into a heating compartment and a drying compartment, means for reifecting a contin nous circulation of air through said com' partments said chamber being provided i lwith anV air inlet and an air outlet, and

means for simultaneously controlling the volume'l of air admitted to the chamber and the volume discharged therefrom.

`or chamber, said chamber 'beingdivided into a discharge of air from Y 5. A drier comprising a suitable casing a heating compartment and a drying comcirculation of air through said compartment-sin 'a path lying lWholly within the chamber, means for effecting and controllin the chamber in a path parallel with the circulation path and simultaneously therewith controlling the influx of fresh air to the chamber.

6. A drying apparatus comprising a suit-v tions, each of said Sections being divided able casing or chamber, said chamber being divided into a heating compartment land a drying compartment, a heating element and a fan in the heating compartment to one side thereof, said fan having an intake communicating with the heating compartment and an outlet communicating with the drying compartment at one'side thereof,'the heating and drying compartments being in communication on the side opposite to the fan outlet, a series of deflectors for causing the air to circulate through the drying compartment in substantially horizontal paths,a flue disposed on the outside of the casingon the opposite side from the fan, the bottom of said flue communicating with the drying compartment, 'the heating compartment having a fresh air intake yadjacent said flue, and operatively associated dampers for controlling the supply of air to the fresh air intake and dischargeof air from said flue.

7. The method of drying materials Which consists in successively subjecting the material to a series of independentheated air circulations, and independently regulating the humidity of the air in said circulations by fresh influxes of comparatively dry air under control. f

8. The method of dryin materials which consists .in successively su jecting the material to a series of independent heated air circulations alternately directed in opposite directions, and independently regulating the humidity of the air -in said circulations by fresh influxes of comparatively dry air under control.

9. A drier comprising a suitable casing, saidcasing being divided longitudinally into a series of communicating juxtaposed secinto-a'heating compartmentand a drying compartment, means for effecting a continu ous circulation of air through the compartents of each section, and means for iny,dependently controlling the volume of air to each section and the volume of air discharged therefrom. In testimony whereof I hereunto aiiix my signature.

u HENRY BAETZ.-

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